<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <table id="smapleTable" border="1">
        <tr><td>Row1 cell1</td>
        <td>Row1 cell2</td></tr>
        <tr><td>Row2 cell1</td>
        <td>Row2 cell2</td></tr>
    </table><br>
    <input type="button" onclick="insert_Row()" value="Insert row"></input>
    <script>
        function insert_Row() {
            tableObj=document.getElementById("smapleTable");
            var currentRow=tableObj.rows.length+1;
            var tr=document.createElement("tr");
            for(let i=0;i<tableObj.rows[0].cells.length;i++){
                let td=document.createElement("td");
                let textNode=document.createTextNode("Row"+currentRow+" cell"+(i+1));
                td.append(textNode);
                tr.append(td);
            }
            tableObj.append(tr);
        }
    </script>
</body>
</html>